One way a wellbore or zone is stimulated and stimulated is using a series of balls that get progressively larger that land on seats sequentially in an uphole direction. Each time a ball is landed and a portion of the zone is isolated the pressure is built up and fractures are initiated and then propagated as the fluid with proppants is delivered at high flow rates and at high pressure. Other stimulation methods such as acid stimulation can utilize the same method. Outside the string is a series of packers so that the fractures or stimulation are initiated between two set packers in the annular space between the bottom hole assembly and the borehole wall. Eventually the stimulation sleeve tripping balls are either flowed out of the hole when the production string is connected or they disintegrate or otherwise go away. Where the zone is treated pressures used to create the fracture or stimulation can create an overpressured condition or in some cases depending on fluid weights an underbalanced condition can be created which would cause the well to want to flow thus creating a potentially unsafe condition. In some instances, intervals that have been stimulated can begin to have significant fluid losses due to fluid weights and reservoir bottom hole pressures again an undesirable and potentially unsafew condition, there is a need for a barrier valve to retain the formation pressure or control fluid losses as opposed to killing the well with heavy fluids or spotting fluid loss control pills to stabilize wellbore fluids and pressures.
Barrier valves typically are hydraulically operated with control lines conducting hydraulic pressure from the surface to an operating piston or pistons for moving a slide that is eccentrically connected to the ball in the barrier valve. When the slide moves, the ball in the barrier valve rotates shut. The barrier valve is normally run in the borehole in an open position. The control lines have to run through a subsea wellhead in some applications. Ultra deep well locations for the barrier valve mean that one or two control lines have to be run from the surface to the barrier valve at great expense. A single control line system typically works against a pressurized chamber in the barrier valve while a two line system connects to an opposite side of an actuating piston for rotation of the ball in a barrier valve. Ball type barrier valves are sometimes referred to as formation isolation valves.
The barrier valve can also be mechanically actuated with a shifting tool on a supporting string that engages an operating sleeve whose axial movement results in 90 degree ball rotation of the barrier valve. The problem with this mode of operation is that the shifting tool restricts or limits the maximum tripping ball size used to actuate the sleeves during stimulation or alternately it requires a trip in the hole to operate the valve with the shifting tool after stimulation treatments. Alternatively, if the production string is to have the shifting tool on the lower end then the barrier valve cannot be closed until the production string is run and safety issues of the formation coming in occur or the well needs to be killed with heavy fluid to allow the production string to be run in with the well under control.
The hydraulically actuated barrier valves require the expense and risk of damage to one or more control lines.
Other types of barrier valves have been designed to operate on tubing pressure. These typically involve the use of j-slots and pressure cycles that after a predetermined number of pressure application and removal cycles the barrier valve operates. The problem with these designs is that the sequential ball dropping and pressure application that takes place in multi-zone stimulation jobs would have the undesirable effect of operating the valve before it was needed to operate. Experience shows that it would also introduce the complexity of having to keep track of how many cycles there were in the middle of other activities that happen at the surface at the same time. Some of these pressure cycle actuated barrier valves and other designs with complex electrical signaling or hydraulic system actuators are shown in U.S. Pat. No. 9,068,417; U.S. Pat. No. 8,365,832; US20120267119; U.S. Pat. No. 8,261,817; US20150136392; U.S. Pat. No. 8,893,798 and U.S. Pat. No. 7,051,812; U.S. Pat. No. 6,041,864.
The present invention provides a simple way to actuate the barrier valve closed without intervention while also allowing the barrier valve to be later reopened without having to keep track of pressure cycles during stimulation or other operations that require pressure to be applied during completion operations. The valve is operable with tubing pressure. Sleeves are shifted with landed balls to expose access to short hydraulic lines or passages that communicate with the actuator for the barrier valve to turn the ball. The balls that land on seats on the sleeves eventually disintegrate or disappear. These and other features of the present invention will be more apparent to those skilled in the art from a review of the detailed description of the preferred embodiment and the associated drawings while recognizing that the full scope of the invention is to be determined by the appended claims.